The dempsey would be fine with them and the oscar gets VERY big so you will need atleast a 55 gallon. And you cant keep african and south/central cichlids together, Africans will kill them.
When dempseys and green terrors mature they are very beautiful fish. I suggest if your ordering a dempsey try your best to get a male. they look alot better. females just have the blue gill plate, while males have a very sparkley body.
When dempseys and green terrors mature they are very beautiful fish. I suggest if your ordering a dempsey try your best to get a male. they look alot better. females just have the blue gill plate, while males have a very sparkley body.